Predetermined torque release hand tool



Oct. 30, 1956 E. F. NoELl.

PREDETERMINED TORQUE RELEASE HAND TooL Filed April 28, 1954 Y.

2 Sheets-Sheet l INVENTOR. finit-,f A/ofu..

ATTOQNEYS.

Oct. 30, 1956 E. F NOELL 2,768,547

PREDETERMINED TORQUE RELEASE HAND TOOL Filed April 28, 1954 2 Sheets- Sheet 2 INVENTOR. M5? c VOELL,

ATTORNEYS.

United States Patent PREDETERMINED TORQUE RELEASE HAND TOOL Elmer F. Noell, Cincinnati, Ohio,` assignor to The Print.- ing Machinery Company, Cincinnati, Ollio, a corporation of Ohio Application April 28, 1954, Serial No. 426,216'

My invention relates to keys for operating printing. plate hooks and particularly for a special combination ofv parts in a key which is controlled by spring pressure so that the key will be inhibited after a certain: torque has been delivered either with clockwise ork counterclockwise operation.

In the art it is common practice in setting electrotype plates on the beds of at bed printing pressesor on cylinder presses to secure the plates in position by adjusting against the side edges of the'plates-clamping devices called hooks7 which are tightened and' loosened by the insertion of a key with a squared end into the squared holes of the part which causes actuation of the jaw to move into engagement with an edge of the plate.

Sometimes the base will have a series of honey-combed holes into which the bodies of the hooks lit. Sometimes the base Will have channels with tracks along their bottorn edges for receiving the bodies of the hooks. In either event the actuating device for the hooks is a key. The hooks are normally tightened against the edges of the electrotype plate by inserting the key into the-squared holes in those elements of the hooks which cause movement of the jaws into engagement with the plate edges and turning in a clockwise direction. For loosening the hooks the key is turned in a counterclockwise direction.

It is important that the torque delivered by the key should be controlled because otherwise the key is liable to twist olf within the hook. The shearing olf of the key requires the complete dismounting of the plate and long and costly delays in remounting the plates on the bed result.

Further excessive torque applied by the key to the hook causes the hook jaw to press so tightly against the electrotype plate as to cause it to buckle. This ruins the plate or if the buckle is slight it can pass as unobserved, but when the printing is completed a poor job will be done.

It is the object of my invention to provide a key having a spindle held against free rotation by spring pressure. It is my object to so direct the spring pressure against the spindle carrying the key that when a certain torque is delivered yeither by clockwise or counterclockwise rotation the Spindle will slip and be inhibited until such time as the torque again builds up by further rotation of the key.

Torque wrenches or various types having a central spindle which rotates and in which springs are so arranged as to release or inhibit the applied torque after a certain spring pressure has been built up are well known in the art. But such torque wrenches, as far as I am advised, all have ratchet arrangements to permit free rotation of the spindle in a counterclockwise direction of movement. Such an arrangement would completely lack utility in a key for adjusting the clamp hooks holding electrotype plates on a printing press bed or cylinder. Such keys must turn clockwise to tighten the hooks and counterclockwise to loosen the hooks. A key which rotated freely in a counterclockwise direction would have no utility in loosening the hooks. Also, as illustrated, the key must be of My invention and the various` combination of parts in the several modifications of keys illustrated and described` are predicatedv ony the discovery that the control byy spring pressure of the torque which may be applied by a key turningl clockwise is exactly the right amount of' torque controlY required by the key turning counterclockwise to always be effective in a counterclockwise or hook' looseningv operation. Describing the operation; the hooks are tightened by clockwise operation of the key. When a certain torque has been delivered the key slips and avoids being sheared off.. But this same torque control in a counterclockwi'se movement is adequate to cause the key to loosen the hook. If this torque control to prevent shearing olf becomes operative with the expenditure of an amount of energy represented by the symbol X, less than this same energy quotient X will be adequate for releasing the hook by a counterclockwise movement'.

The foregoing. objects and other objects which will be subsequently described IV accomplish by that combination of parts of which I have shown several modifications, which are about eight times actual size.

Referring to the drawings:

Figure l is a4 perspective view of one type of key in which the key spindle is provided with a series of vertically arranged slots.

Figure 2 is a. sectional' view of the key illustrated inA Figure l alongV the lines' 2 2 showing the internal construction.

Fig. 3 is a perspective View of one of the spring pressed plungers.,

Figure' 4 is a sectional view as would appear along the lines 4 4 of Figure 2.

Figure 5 is a front elevation with parts in section showing al different type of key spindle.

Figure 6 is a sectional view along the lines 6-6 of Figure 5.

Figure 7 is a perspective View of the key spindle of Figures 5 and 6.

Figure S is a perspective view of one of the plungers of Figures 5 and 6.

Figure 9 is a front elevation with parts in section of a sti-ll further modication of key spindle.

Figure l0 is a perspective view of the key spindle of Figure 9.

Figure ll is a sectional view along the lines lil-11 of Figure l0.

Referring first to the modifications illustrated in Figures l-4, the key is formed with a cross barrel 1 having a center hole or bore 2, which receives the rotary spindle 3 having a splined thumb post 4 which extends from the spindle. It is a feature of my invention that vthe thumb post 4 extends up substantially from the cross barrel as illustrated to provide an adequate handle which may be grasped in the lingers for turning the key. The lower end of the spindle has a squared hole which receives the key S. The key is tightened within the squared hole by a set screw 6.

The spindle has a series of circumferentially equally spaced V-shaped slots 7. Within the cylindrical opening or cross bore e in the barrel there are, on opposite sides forced inwardly by the springs 9, the plungers l?, each having an angular ridge 11, which, as will be obvious lit within the V-shaped slots of the spindle. At one end of the cylindrical opening there is a plug l2 held in position by a pin 13. Such construction facilitates the assembly of the key.

In Figures 5 to 8, the parts are numbered in the same way as Figures l to 4, with the letter a added to the ordinal. Thus there is the cross barrel la, spindle 3a fitting within the hole 2a with the key 5a held in position by the set screw 6a. Instead of the lengthwise slots 7 of the modication illustrated in Figures 1 to 4, the spindle has flattened portions 7a against which the flat headed plungers 10a bear with the pressure of the springs 9a 0n each side urging the plungers against thee attened portions of the spindle. A plug 12a is held in position by a pin 13a.

In Figures 9-11 the spindle 3b ts Within the hole 2b in the cross barrel 1b. The key 5b is held in the barrel by the set screw 6b. The spindle is provided with a series of cup shaped recesses 7b into which fit the rounded heads 10b of the plungers. The plungers are forced inwardly by the springs 9b. The spindle 3b has a knurled head 4b and a plug 12b is held in the end of the barrel by a pin 13b.

It should be understood that my invention is primarily in the substitution of my preferred type of key for the normal key used for tightening any type of hook as long as it operates with a squared key.

In use the operator positions his electrotypes or printing plates on the bed and then inserts the hooks bearing against the edges of the plates. It will be impossible to shear off the key because when suicient torque is delivered the spindle will slip and release the tension on the key. At the same time, while the torque is controlled by the spring arrangements when the key is turned clockwise, the spring tension is adequate to permit actuation of the worm shaft in the hook with counterclockwise rotation of the key. Irrespective of the tightness with which the hook is clamped the key will always loosen it. This is because the force required to tighten the hook is always greater than the force required to unloosen it. It is on the basis of this discovery that my invention is predicated.

1t is a feature of my invention that the lengthwise play of the key spindles in the cross members is controlled only by the elements actuated by spring pressure bearing against the recessed portions of the spindles. If the springs are removed the spindles may be withdrawn from the cross members. Such construction greatly facilitates the assembly of the keys in factory operations and makes it practical to produce such torque controlled keys in quan tity. Also the fact that the spindles are held in position only by the springs and plungers eliminate many steps in factory operation. There are no closely machined parts which must tit exactly to make the devices operable.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

A predetermined torque release hand tool for use as a key for printing plate registering hooks comprising a splined spindle having a squared opening at its lower end in which a key is received, a screw opening into said squared opening adjacent the lower end of said spindle for engaging said key, and a manually operable cross bar member of greater length than width, said cross bar member having a cylindrical bore extending from top to bottom through which said spindle extends, said cross bar member having a longitudinally extending internal bore in which are mounted an opposed pair of spring pressed plungers having nose portions engageable in the splines of the spindle, said plungers acting to provide a torque release upon the rotation of the cross bar at a predetermined turning moment, said spindle being maintained within the cylindrical bore of the cross bar member solely by the pressure of the plungers thereagainst.

References Cited in the tile of this patent UNITED STATES PATENTS 445,615 Rathbun Feb. 3, 1891 1,165,159 Dunner Dec. 2l, 1915 2,106,319 Federighi Jan. 25, 1938 2,164,870 De Salardi July 4, 1939 2,503,499 Livermont Apr. ll, 1950 2,601,044 Mayer June 17, 1952 2,601,799 Garwood July l, 1952 FOREIGN PATENTS 352,005 Italy Aug. 31, 1937 

